The Analytical Facility Core (directed by Dr. Mark Shigenaga) is an extensive facility for detailed analytical chemistry. The facility consists of eight high-pressure liquid chromatographic apparatuses, many with fluorescent detectors and electrochemical detectors, two mass-specs, and other peripheral instrumentation. The major effort in the facility is to analyze DNA adducts, particularly 8-hydroxyguanosine, and other adducts formed by oxygen damage to DNA as well as novel nitrotyrosines with monoclonal antibodies. The facility operates as both an analytical chemical facility and as a teaching facility. The analytical facility has developed several procedures which are key to the past and proposed work of the Center including: analysis of antioxidants; quantifying oxidative changes in vitro and in vivo, and quantifying oxidative changes in DNA. Most procedures have been published. Drs. Ames, Linn, Karu, and Block are primary users but several other researchers benefit directly and indirectly from the analytical efforts. The efforts of this core are also of value to researchers at institutions other than Berkeley.